Fabrication of Co-Cr film with large perpendicular anisotropy using a roll coater system.

A roll coater system was investigated for establishment of a mass production system for Co-Cr perpendicular recording media. Improvements of the crystal orientation and the magnetic properties of Co-Cr media with the introduction of new seed layers of Co-Cr itself are described. In the light of these results, a Co-Cr film with a composition gradient in the growing direction but without any seed layer has been proposed and its properties discussed. It was found that the anisotropy field Hk can be remarkably increased for the film with a composition gradient over that of a conventional Co-Cr film. It is concluded that the newly developed Co-Cr film is very suitable for mass production by a roll coater because of its simplified process which requires no sputtering of any seed layers.